Expanding Habitat for Rare, Threatened and Endangered Species

It’s a great feeling knowing that ACRES protects and stewards many areas that rare, threatened and endangered species call home. However, the number of plants and animals listed as rare is unsettling.

Between 2016 and 2023, two species were removed from the list of federally protected species present in Indiana as a result of recovery efforts. However, during that same time frame, seven species were added to the list due to a sharp decline in their populations. As the list grows, it’s becoming easier to find species classified as Rare, Threatened or Endangered.

Rare, Threatened and Endangered (RTE) species are referred to as such primarily due to habitat loss. It makes sense that most RTEs occupy the least common plant communities — often those significantly reduced or degraded through development and other landscape alterations such as tiling and ditching. Another way of thinking about it is that most of Indiana’s RTE species inhabit a tiny percentage of the available area. This translates into many relatively isolated, high-quality regions where these species are found. Historically, these areas would have been more prominent, and in many cases, would have had some connection with neighboring high-quality areas.

For all these reasons, ACRES prioritizes acquisitions in predetermined conservation areas that offer high levels of biodiversity and acquisitions that expand existing preserves with rare plant communities. To maximize our impact, stewardship activities are also prioritized within these areas.

Each year, ACRES learns more about these unique areas by completing botanical inventories that help paint a picture of the landscape while often uncovering RTE plants unnoticed for years or decades. By uncovering RTE plants, our inventories play a vital role in shaping our preserve management plans for years to come.

Since critters tend to be a bit more mobile, finding RTE animals can be a little trickier than finding RTE plants. However, these critters also tend to inhabit our more unique plant communities, making it a little easier to know where to look. ACRES is quick to help whenever we can partner with a university that aims to learn more about specific species. A great example of what happens when looking for RTE species can be seen when diving into the recent work that Dr. Scott Bergeson (Assistant Professor of Animal Biology – Purdue FW) conducted within the Cedar Creek corridor. Bergeson set out to determine which species of bats were inhabiting the area surrounding an ACRES property in the corridor. These surveys aimed to locate a population of little brown bats. Although no little brown bats were found, Bergeson, along with a handful of students and ACRES interns, turned up both the federally endangered Indiana bat and the federally endangered northern long-eared bat.

Bergeson explained: “Both species were already suffering from habitat loss when whitenose syndrome (a fungal disease that can’t hurt humans) started causing massive numbers of bat mortality. These bat species, especially the northern long-eared bat, are now rarely captured in Indiana. The fact that these two endangered species were found in the Cedar Creek corridor suggests that the area is prime habitat. The bats likely rely on standing dead trees (snags) along the creek to provide them with day-time roosts.”

Sometimes we find RTE critters unexpectedly while documenting plants. This was the case earlier this summer when Nathanael Pilla of Midwest Biological Consulting was conducting a botanical inventory at ACRES Fawn River Nature Preserve. While documenting plants, we found ourselves following and snapping pictures of unfamiliar dragonflies! One turned out to be the Green-faced clubtail, rare in Indiana and documented in only 3 counties in the state (and not in LaGrange County) since the 1930s.

On the same visit, Pilla and the ACRES crew were also accompanied by Dr. Marc Milne (Associate Professor of Biology at the University of Indianapolis), our regional spider expert. Within a few hours, Milne had collected nearly 100 spiders that would need to be more closely examined under a microscope to identify. Milne identified four new state records by identifying four species of spiders not previously known to be present in Indiana. Within just a few hours of searching, several rare critters had been documented, not to mention the hundreds of plants being jotted down along the way.

With ACRES history of acquiring and protecting high-quality natural areas, we usually find RTE species when we take time to look for them. In coming years, we hope to see the rate at which new species are added to the list of Indiana’s Rare, Threatened and Endangered species slow as we and our partners provide permanent protection to more large contiguous natural areas.

This article originally appeared in the Winter 2023 ACRES Quarterly, mailed to members each season. The 20-page Quarterly features ACRES news, stories and events. You can subscribe by becoming an ACRES member with a donation of $20 or more. Click here to learn more!